CN101969208B - Method for inhibiting subsynchronous resonance of wind power system - Google Patents

Method for inhibiting subsynchronous resonance of wind power system Download PDF

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CN101969208B
CN101969208B CN2010102964696A CN201010296469A CN101969208B CN 101969208 B CN101969208 B CN 101969208B CN 2010102964696 A CN2010102964696 A CN 2010102964696A CN 201010296469 A CN201010296469 A CN 201010296469A CN 101969208 B CN101969208 B CN 101969208B
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series compensation
controlled series
capacitance voltage
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trigger delay
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汤奕
郁瑞倩
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Southeast University
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Abstract

The invention relates to a method for inhibiting the subsynchronous resonance of a wind power system. Based on a controlled series compensation method, a trigger delay angle of a controlled series compensation thyristor valve group is controlled and the current of a valve group reactor L is adjusted, so that controlled series compensation equivalent impedence is controlled, the equivalent impedence is corrected in a closed-loop control mode, and the trigger delay angle is corrected in real time. The method is characterized in that: by adopting a PSCAD/EMTDC software and MATLAB software joint operation mode and based on an MATLAB computing method and phase shift between capacitor voltage zero-crossing moment and synchronous turnover moment, an additional damping control algorithm is designed, the controlled series compensation real trigger delay angle is calculated and the subsynchronous resonance is inhibited.

Description

A kind of method that suppresses the wind power system subsynchronous resonance
Technical field
The present invention relates to the wind-electricity integration technology, relate in particular to a kind of method that suppresses the wind power system subsynchronous resonance.
Background technology
Along with the development and the maturation of wind generating technology, the installed capacity of wind-powered electricity generation unit is increasing, this means that the existing electrical network of the extensive access of wind power generation power becomes a kind of inevitable trend.Consider the grid structure characteristics of wind energy turbine set and electrical network,, improve road along the line voltage and distribute that using serial compensation capacitance then is a kind of effective means in order to improve the wind-powered electricity generation through-put power that inserts electrical network.Yet the access of serial compensation capacitance will cause hyposynchronous resonance of power system (SSR) simultaneously, thereby jeopardize the safe and stable operation of electrical network.In order to suppress this destructive phenomenon, use controlled series compensation (TCSC) to replace fixed series compensation usually, and realize functions such as trend control and raising transient stability simultaneously.
Controlled series compensation device main circuit structure sketch map is as shown in Figure 1, mainly is made up of series capacitor bank C, valve control reactance L and anti-parallel thyristor valve group.Through the thyristor valve group trigger delay angle of control TCSC, the electric current of control valve group reactance L, thus realize control controlled series compensation equiva lent impedance, reach the purpose of other physical quantity of regulating and controlling electric power system such as voltage, active power, reactive power etc.
Controlled series compensation has very big relation to the inhibition effect of subsynchronous resonance and the control mode of controlled series compensation itself.Existing controlled series compensation control mode has open loop control, closed-loop control etc.Open loop control is the open loop impedance Control, and but its control strategy is simple, be easy to realize can't revise the trigger delay angle, thereby the control effect is limited.How closed-loop control has controlled the FEEDBACK CONTROL link with respect to open loop; The trigger delay angle is revised in control through to impedance, electric current or active power in real time; One adopts proportional integral (PI) link controller, and the control effect is influenced by the parameter of this link, selected controlled quentity controlled variable.Thereby for different trigger delay angle set points, the parameter of PI link is different, and the control effect is difference to some extent also.
Summary of the invention
The present invention is directed to the deficiency of prior art; In order further to improve the damping of controlled series compensation (TCSC) to wind power system SSR oscillation mode; A kind of method of effective inhibition wind power system subsynchronous resonance has been proposed; This method adopts PSCAD/EMTDC software and MATLAB software cooperation mode based on controlled series compensation (TCSC), based on the phase shift between the capacitance voltage zero passage moment and the synchronizing voltage upset constantly; Realization is to the control at controlled series compensation trigger delay angle, thereby reaches the purpose that suppresses subsynchronous resonance.
The technical scheme that the present invention takes is:
A kind of method that suppresses the wind power system subsynchronous resonance; Be the basis with the controlled series compensation method; Through the thyristor valve group trigger delay angle of control controlled series compensation, the electric current of adjuster valve group reactance L is realized the control to the controlled series compensation equiva lent impedance; And then adopt the impedance of close-loop control mode equivalent to proofread and correct, revise the trigger delay angle in real time; It is characterized in that: adopt PSCAD/EMTDC software and MATLAB software cooperation mode; On the basis of MATLAB computational methods; Phase shift between overturning constantly constantly and synchronously based on the capacitance voltage zero passage; Design additional damping control algolithm, the actual trigger delay angle of asking for controlled series compensation, concrete steps are following:
(1) measurement, sampling obtain comprising capacitance voltage, and line current is at interior local data;
(2), from the capacitance voltage that measures and line current, extract fundamental component separately based on the quick Fourier transformation algorithm;
(3) according to fundamental frequency capacitance voltage component and fundamental frequency line current component, calculate the equiva lent impedance of controlled series compensation under fundamental frequency according to Ohm's law;
(4) by the line current information that measures, obtain the initial synchronisation reference signal, as an input signal of lifting factor controller through phase-locked loop;
(5) imaginary part of equiva lent impedance is that equivalent reactance is by the physics reactance X of controlled series compensation capacitive branch C0After the normalization with lifting factor reference value K RefThe factor that gets a promotion relatively deviate Δ K, Δ K is input to the lifting factor controller together as another input signal and the initial synchronisation reference signal of lifting factor controlling unit, and it is output as the reference synchronization time series;
Obtain reference synchronization time series concrete steps:
1), goes out the phase shift
Figure BDA0000027401520000021
between the actual capacitance voltage zero-cross moment and the synchronizing voltage upset constantly according to computes according to lifting factor deviate Δ K
Figure BDA0000027401520000022
In the formula, s is the Laplace operator, f NBe fundamental frequency;
2) confirm the reference synchronization time series according to
Figure BDA0000027401520000023
and the initial synchronisation reference signal of calculating gained;
(6) according to capacitance voltage, the line current measured value in a certain moment, calculate based on MATLAB software:
1) measure capacitance voltage and line current, record is measured constantly, and confirms capacitance voltage zero passage t constantly by the reference synchronization time series z, go out at this zero passage moment capacitance voltage u (t according to computes then Z) actual value:
u(t Z)＝u(t M)+X 0i(t M)kω N(t Z-t M)
In the formula, k=ω 0/ ω N,
Figure BDA0000027401520000024
ω NAngular speed during for fundamental frequency, i (t M) and u (t M) be respectively t MThe instantaneous value of time line electric current and capacitance voltage;
2) according to the u (t that calculates Z), go out controlled series compensation by computes and trigger angle of retard β:
u(t Z)＝X 0i(t M)[kβ-tan(kβ)]
3) according to the β that calculates, go out the real-time trigger delay of controlled series compensation angle α by computes:
α＝ω Nt Z-β
(7) by the trigger delay angle α of MATLAB output calculating gained, the control controlled series compensation triggers in PSCAD/EMTDC software, for controlled series compensation provides the suitable trigger pulse, realizes suppressing subsynchronous resonance.
The invention has the beneficial effects as follows:
(1) adopts the local information amount as input signal, be easy to realize;
(2) directly the control capacitance voltage zero-cross is realized controlled target constantly;
(3) height of having avoided between trigger delay angle and the capacitance voltage is non-linear, makes the controlled series compensation equiva lent impedance in subsynchronous frequency range, be perception, can effectively suppress SSR.
Description of drawings
Fig. 1 is a prior art controlled series compensation TCSC main circuit structure sketch map;
Fig. 2 is PSCAD/EMTDC of the present invention and MATLAB interface structure figure;
Fig. 3 is an implementation procedure block diagram of the present invention.
Embodiment
The present invention is based on PSCAD/EMTDC software and MATLAB software cooperation mode; Utilize the computing function of MATLAB; Can design the additional damping control algolithm,, propose a kind of method of asking for the trigger delay angle of controlled series compensation TCSC through MATLAB; By the trigger delay angle that gained is calculated in MATLAB output, the control controlled series compensation triggers in PSCAD/EMTDC software.
The sketch map of PSCAD/EMTDC of the present invention and MATLAB cooperation structure is as shown in Figure 2.A Fortran file DSDYN is arranged in the PSCAD/EMTDC, can call outside Fortran subroutine through it.This Fortran subroutine can start the MATLAB data engine and set up Fortran subroutine and the MATLAB data engine between communication pipe; Simultaneously; The M file that contains the MATLAB order also passes in the MATLAB data engine, and P SCAD/EMTDC and MATLAB just closely combine like this.Comprise following several links here:
(1) in PSCAD/EMTDC, measures, samples, thereby obtain capacitance voltage u C, line current i LDeng local data, and these data are input in the MATLAB data engine;
(2) numerical computations, according to the local data that obtains, based on MATLAB language M file, the trigger delay angle α of controlled series compensation is calculated in programming;
(3) data output, by the trigger delay angle that gained is calculated in MATLAB output, the control controlled series compensation triggers in PSCAD/EMTDC software.
PSCAD/EMTDC and MATLAB cooperation structure can improve the disposal ability of PSCAD software to data, make that the calculating to nonlinear equation becomes possibility in PSCAD/EMTDC.
Below, in conjunction with Fig. 3 practical implementation process of the present invention is described in detail.
Based on the actual situation that inserts electrical network of prior art controlled series compensation (structure is seen Fig. 1), it realizes that the whole implementation procedure that suppresses subsynchronous resonance comprises following a few part:
(1) DATA REASONING: use measurement mechanism,, measure capacitance voltage and line current like voltmeter and ammeter;
(2) phasor assessment:, from the capacitance voltage that measures and line current, extract fundamental component separately based on the quick Fourier transformation algorithm;
(3) equiva lent impedance Z asks for: according to before the fundamental frequency capacitance voltage component and the fundamental frequency line current component of trying to achieve, calculate the equiva lent impedance Z of controlled series compensation under fundamental frequency according to Ohm's law;
(4) obtain the initial synchronisation reference signal: according to the line current information that measures, obtain the initial synchronisation reference signal through phase-locked loop, and as an input signal of lifting factor controller;
(5) obtain the reference synchronization time series: the imaginary part of equiva lent impedance is that equivalent reactance is by the physics reactance X of TCSC capacitive branch C0After the normalization, will with lifting factor reference value K RefThe factor that gets a promotion relatively deviate Δ K, this lifting factor deviate is input to the lifting factor controller together as another input signal and the initial synchronisation reference signal of lifting factor controlling unit, and it is output as the reference synchronization time series.
The reference synchronization time series of obtaining described herein specifically may further comprise the steps:
Step 1:, calculate the phase shift
Figure BDA0000027401520000031
between the actual capacitance voltage zero-cross moment and the synchronizing voltage upset constantly according to following formula (1) according to lifting factor deviate Δ K
Figure BDA0000027401520000032
In the formula, s is the Laplace operator, f NBe fundamental frequency.
Step 2:
Figure BDA0000027401520000041
and initial synchronisation reference signal by step 1 gained are confirmed the reference synchronization time series by the phase place addition.
(6) produce the trigger impulse sequence:,, obtain the trigger delay angle according to trigger delay angle acquiring method, for TCSC provides the suitable trigger pulse according to reference synchronization time series, capacitance voltage and line current based on the SVR trigger generator.
Asking for controlled series compensation trigger delay angle specifically may further comprise the steps:
Step 1: measure capacitance voltage, line current, and write down and should measure constantly, according to confirm capacitance voltage zero passage t constantly by the reference synchronization time series z, calculate the desirable zero passage of capacitance voltage capacitance voltage u (t constantly according to following formula (2) then Z);
u(t Z)＝u(t M)+X 0i(t M)kω N(t Z-t M) (2)
In the formula, k=ω 0/ ω N,
Figure BDA0000027401520000042
ω NAngular speed during for fundamental frequency, i (t M) and u (t M) be respectively t MThe instantaneous value of time line electric current and capacitance voltage.
Step 2: by step 1 gained u (t Z), calculate controlled series compensation according to following formula (3) and trigger angle of retard β;
u(t Z)＝X 0i(t M)[kβ-tan(kβ)] (3)
Step 3:, calculate the real-time trigger delay of controlled series compensation angle α according to following formula (4) by step 2 gained β.
α＝ω Nt Z-β (4)

Claims (1)

1. method that suppresses the wind power system subsynchronous resonance; Be the basis with the controlled series compensation method; Through the thyristor valve group trigger delay angle of control controlled series compensation, the electric current of adjuster valve group reactance L is realized the control to the controlled series compensation equiva lent impedance; And then adopt the impedance of close-loop control mode equivalent to proofread and correct, revise the trigger delay angle in real time; It is characterized in that: adopt PSCAD/EMTDC software and MATLAB software cooperation mode; On the basis of MATLAB computational methods; Based on the phase shift between the capacitance voltage zero passage moment and the synchronizing voltage upset constantly; Design additional damping control algolithm, the actual trigger delay angle of asking for controlled series compensation, concrete steps are following:
(1) local data that measure, sampling obtains comprising capacitance voltage, line current;
(2), from the capacitance voltage that measures and line current, extract fundamental component separately based on the quick Fourier transformation algorithm;
(3) according to fundamental frequency capacitance voltage component and fundamental frequency line current component, calculate the equiva lent impedance of controlled series compensation under fundamental frequency according to Ohm's law;
(4) by the line current information that measures, obtain the initial synchronisation reference signal, as an input signal of lifting factor controller through phase-locked loop;
(5) imaginary part of equiva lent impedance is that equivalent reactance is by the physics reactance X of controlled series compensation capacitive branch C0After the normalization with lifting factor reference value K RefThe factor that gets a promotion relatively deviate Δ K, Δ K is input to the lifting factor controller together as another input signal and the initial synchronisation reference signal of lifting factor controlling unit, and it is output as the reference synchronization time series;
Obtain reference synchronization time series concrete steps:
1), goes out the phase shift
Figure FDA00001726465400011
between the actual capacitance voltage zero-cross moment and the synchronizing voltage upset constantly according to computes according to lifting factor deviate Δ K
Figure FDA00001726465400012
In the formula, s is the Laplace operator, f NBe fundamental frequency;
2) confirm the reference synchronization time series according to
Figure FDA00001726465400013
and the initial synchronisation reference signal of calculating gained;
(6) according to capacitance voltage, the line current measured value in a certain moment, calculate based on MATLAB software:
1) measure capacitance voltage and line current, t constantly measured in record M, and confirm capacitance voltage zero passage t constantly by the reference synchronization time series z, go out at this zero passage moment capacitance voltage u (t according to computes then Z) actual value:
u(t Z)=u(t M)+X 0i(t M)kω N(t Z-t M)
In the formula, k=ω 0/ ω N,
Figure FDA00001726465400014
With
Figure FDA00001726465400015
C is the electric capacity of the series capacitor bank of controlled series compensation, ω NAngular speed during for fundamental frequency, i (t M) and u (t M) be respectively t MThe instantaneous value of moment line current and capacitance voltage;
2) according to the u (t that calculates Z), go out controlled series compensation by computes and trigger angle of retard β:
u(t Z)=X 0i(t M)[kβ-tan(kβ)]
3) according to the β that calculates, go out the real-time trigger delay of controlled series compensation angle α by computes:
α=ω Nt Z-β
(7) by the trigger delay angle α of MATLAB output calculating gained, the control controlled series compensation triggers in PSCAD/EMTDC software, for controlled series compensation provides the suitable trigger pulse, realizes suppressing subsynchronous resonance.
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CN102651550B (en) * 2012-04-13 2014-07-02 中国电力科学研究院 Sub-synchronous oscillation suppression method based on controllable series compensation additional impedance deviation control
CN103683307A (en) * 2012-09-21 2014-03-26 哈尔滨帕特尔科技股份有限公司 New type series compensated line subsynchronous resonance damping and short-circuit current limiting device
CN105226677B (en) * 2014-11-20 2017-07-28 国家电网公司 A kind of control method for suppressing wind power plant compensated transmission system subsynchronous resonance
CN104638664B (en) * 2015-02-13 2016-08-24 北京四方继保自动化股份有限公司 Wind park sub-synchronous oscillation guard method and protection device
CN105470970B (en) * 2015-11-16 2018-02-09 清华大学 The guard method of subsynchronous and supersynchronous vibration and system in power system

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